Process of manufacture of wall board, pressboard, and the like



Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE FERNANDO S OMOZA VIVAS, F BRONXVILLE, NEW YORK PROCESS OF MANUFACTURE OF WALL BOARD, PRESSBOARID, AND THE LIKE No Drawing.

The invention relates to the manufacture.

of cellulosic fibre materials such as wallboard, pressboard, paper or the like and has as an object the provision of a process for producing a superior product.

It is afurther object of the invention to provide a process of manufacturing heavily compressed material of cellulosic fibres, as pressboard, wherein a superior product may be produced with less pressure than that heretofore required.

It is a further object of the invention to provide a process of manufacturing the material of the character described using a novel form of binder to increase the coherence of the fibres.

It is a further object of the invention to provide a process of the character referred to wherein fireproofing materials in accordance with the disclosures of my co-pending applications, Serial Numbers 407,280 and 407,281 filed November 14, 1929, may be added to, the binder provided by the invention so as to produce a fireproof material by the steps of the process.

Further objects of the invention will ap pear from the following description of illustrative embodiments of theinvention.

In furtherance of the objects of the invention the pulp of which the material is to be manufactured is prepared in the usual manner with the addition of a solution in? cluding dextrine to the water in which the 4 pulp is beaten. The amount of dextrine should be such as to provide a specific gravity of the solution in the beater, disregarding the fibres, of from 18- B. at 100 F. temperature to 21 B. at 200 F. temperature depending upon the material being manu-- factured as will be described below.

' In the manufacture of porous wallboard or paper a lower specific gravity and temperature range is preferable but in the manufacture of highly compressed material as pressboard alngher specific gravity should be used. After the pulp has been prepared by heating with the solution described, the material may be formed into a sheet of wallboard or paper in the usualmanner.

When pressboard is to be manufactured, 1t

Application filed December 3, 1929. Sierial No. 411,387.

' ing a temperature of from 350 F. to 400 F.

while the pressure is applied. In accordance with the process of the invention it is found that an equally good or superior product may be secured by a pressure of from 150 to 200 pounds per square inch and that a tempera ture of from 212 F. to 225 F. is sufficient. Because of the lessening of the required pressure and temperature pressboard may be manufactured very much more economically than heretofore.

A modified form of binder containing dextrine which is found preferable for some purposes is described in my application Serial Number 407,281 above referred to and may be prepared as follows: Substantially forty parts of starch are boiled with substantially sixty parts of glycerine until a transparent mass is produced. To the hot materials substantially 100 parts of alcohol are added and stirred with the 30 'massto produce a solution thereof and to cause acooling of the resultant solution. The alcohol may be either methyl or ethyl alcohol and the ethyl alcohol may be that usually sold as denatured alcohol prepared in accordance with any standard formula. The thus prepared solution may be substituted for the plain dextrine solution above referred to to provide a solution for use in the beater of the specific gravity described.

If it is desired to produce fireproof material the fireproofing materials of the abovementioned co-pending applications may be added to the solution as described, utilizing substantially 1 pound 8 ounces of magnesium sulphate, 4. ounces borax, 4 ounces ammonium sulphate, 1.6 ounces alco-glycero-dextrine solution above described; or 1% pounds of magnesium chloride, 4 ounces of boric acid,

' 1 I claim:,

1. The process of producing a sheet of 4 ounces ammonium chloride with 1.6 ounces of the plain dextrine solution.

Minor changes in the steps of the process or in the quantities of ingredients used may be made within the scope of the following claims without departing from the spirit of the invention.

felted cellulosic fibres which comprises beating the pulp in the preparation thereof with a solution'comprising dextrine and forming a sheet from the thus prepared material.

2. The process of producing a sheet of felted cellulosic fibres which comprises beating the pulp in the preparation thereof with a solution of the herein described alcoglycero-dextrine solution and forming a sheet from the thus prepared pulp.

3. The process of producing pressboard which comprises beating a pulp of cellulosic fibres in a solution including dextrine, forming asheet from the thus prepared'pulp, and subjecting the sheet to pressure to express the moisture and to produce a dense body of felted and compressed fibres.

4. The process of producing pressboard which comprises beating a pulp of cellulosic fibres in a solution including dextrine, forming a sheet from the thus-prepared pulp, and subjecting the sheet to pressure and heat to express moisture and set the fibres whereby to produce a dense body of felted fibres.

5. The process of producing pressboard which comprises beating a pulp of cellulosic fibres in a solution including dextrine, forming a sheet from the thus prepared pulp,-

compressing the sheet at a pressure of substantially 200 pounds per square inch and subjecting the sheet while under pressure to a temperature of substantially 225 F. whereby to set the sheet and produce a dense body of felted fibres.

6. The process of producing fireproof pressboard which comprises beating a pulp of cellulosic fibres in a solution comprlsing the herein described alco-glyceroedextrine solution, magnesium and ammonium chlorides and boric acid, forming a sheet from the thus prepared pulp, subjecting the sheet to a pressure of substantially 200 pounds per square inch and to a temperature of substantially 225 F. ,while held under pressure whereby to compress and set the fibres to produce a dense fireproof body of felted .fibres.

FERNANDO SOMOZA. yrvAs. 

